Sera from 264 cancer patients, 196 disease controls and 237 healthy donors have been studied to evaluate whether immune complex-like materials may be found in the sera and whether testing for these will be an effective way to evaluate prognosis in cancer patients and monitor for recurrent tumors. We have mainly used the Clq binding test for this work, but results obtained in that test have been compared with those obtained in the Raji cell assay, a monoclonal rheumatoid factor test and the Clq deviation method. The tests differ somewhat in their results but we can demonstrate that the Clq binding test does provide an effective means to monitor for soluble complexes in sera. Currently, we are making good progress in the isolation and characterization of the molecules responsible for the Clq binding activity in patient sera. BIBLIOGRAPHIC REFERENCE: Rossen, R.D., M.A. Reisberg, E.M. Hersh, J.U. Gutterman. The Clq binding test for soluble immune complexes: Clinical correlations obtained in patients with cancer. J. Natl. Cancer Inst. 58: 1205-1215, 1977.